Spawning season movements of transported landlocked Atlantic salmon in a newly restored river habitat

2020 ◽  
Author(s):  
Aurora Hatanpää ◽  
Hannu Huuskonen ◽  
Matti Janhunen ◽  
Raine Kortet ◽  
Jorma Piironen
Keyword(s):  
Atlantic Salmon ◽  
Release Site ◽  
Low Flow ◽  
River Habitat ◽  
Natural Reproduction ◽  
Spawning Areas ◽  
Salmon Population ◽  
Spawning Time ◽  
Lake Saimaa ◽  
Spawning Habitats

Certain spawning areas of the critically endangered Lake Saimaa landlocked Atlantic salmon (Salmo salar m. sebago) have been recently restored by excavator- and helicopter-scattered gravel, but the success of applied methodologies has remained open. Here, we monitored the spawning-related movements and redds occurrence of transported semi-wild and hatchery-reared salmon in the restored River Ala-Koitajoki, Eastern Finland using radiotelemetry and snorkelling. Nearly all fish accepted the newly-restored spawning habitats in the river that maintains a low flow rate (only 4 m3 s-1). The movements of females released up to two weeks before spawning time were restricted mainly to the closest rapids from the release site, and most of the movements were directed downstream. Semi-wild and hatchery background fish exhibited similar mobility, which was more variable among males. A majority of redds were found in restored areas, and both helicopter- and excavator-scattered gravels were accepted as spawning substrates. Our results indicate that natural reproduction of the studied landlocked salmon population can be successfully returned to its original spawning river by restoration of habitats and transfer of spawners.

Adult Atlantic salmon (Salmo salar) spawning migration and behaviour in the lower Skienselva

2021 ◽  
Author(s):  
Sheryl Schwert
Keyword(s):  
Power Plant ◽  
Atlantic Salmon ◽  
Low Flow ◽  
Upstream Migration ◽  
Hydroelectric Power ◽  
Negative Consequences ◽  
Spawning Period ◽  
Fish Ladder ◽  
Spawning Areas ◽  
Spawning Sites

<p>Atlantic salmon swim upstream from the North sea through Frierfjorden to spawn in the Skien watershed, the third largest in Norway. There are two hydroelectric power plants in the lower reaches of the Skienselva: Klosterfoss and Skotfoss. Salmon caught swimming up the fish ladder at the downstream power plant (Klosterfoss) were tagged, released, and at the downstream power plant tracked from the beginning of the upstream migration to the end of the spawning period in the entire anadromous watershed. Salmon spent unequal amounts of time at the four spawning areas in the main river and a tributary between Klosterfoss and Skotfoss. Salmon spent less time at the larger spawning site, Vadrette, compared to the smaller Fossum and Grøtsund spawning sites. 26% of tagged salmon which swam upstream to the Skotfoss hydroelectric power plant ascended the fish ladder. Further, 16% of all salmon ascended the fish ladder at Skotfoss and continued to upstream spawning sites, indicating that they were homing to sites in the upper watershed. This is much smaller than the what is expected based on the fry populations in the rivers of the Skien watershed, which are augmented by yearly stocking in some of the rivers. Salmon which ascended the Klosterfoss ladder relatively early, swam upstream to Skotfoss more quickly than salmon that arrived relatively late at the Klosterfoss ladder. Short and repeated movements upstream to Skotfoss, and downstream to areas in the Farelva, and back again to Skotfoss were observed in the majority of tagged salmon that approached Skotfoss. The “yo-yo” migration of salmon in the Farelva is for the most part unexplained, but the movement costs the salmon valuable energy before and during the spawning season and may have negative consequences. Overall, these results indicate that salmon find the entrance to the fish ladder and do not remain stuck at the tunnel outlet, but most do not successfully ascend it. This could be the result of poor ladder construction, too low flow from the ladder, low survival of fry from upstream of Skotfoss reducing the number of salmon that are homing to upstream spawning areas, or that not all salmon which approach Skotfoss are homing to areas above the ladder. The possibility exists that salmon which will eventually spawn in areas downstream of the ladder engage in searching behavior near the fish ladder. If efforts to restore the populations in the upper watershed are to continue, issues salmon have with ascending the Skotfoss fish ladder must be addressed first.</p>

Persistence of a southern Atlantic salmon population: diversity of natal origins from otolith elemental and Sr isotopic signatures

2013 ◽  
Vol 70 (2) ◽  
pp. 182-197 ◽  
Author(s):  
Jean Martin ◽  
Gilles Bareille ◽  
Sylvain Berail ◽  
Christophe Pécheyran ◽  
François Gueraud ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Function Analysis ◽  
Population Diversity ◽  
Isotopic Signatures ◽  
Natal Origin ◽  
Natural Tags ◽  
Quadratic Discriminant Function ◽  
Spawning Areas ◽  
Salmon Population

We investigated the use of Sr:Ca, Ba:Ca, and 87Sr:86Sr ratios as natural tags for determining the natal origins of juvenile and adult Atlantic salmon (Salmo salar) from 12 tributaries in the Adour basin (southwestern France) and estimated homing on a tributary scale. Geochemical signatures from core regions of the otolith were also used to identify fish from hatchery or naturally spawned sources. Quadratic discriminant function analysis (QDFA) was on average 80% successful at classifying juveniles according to their natal rivers. Adults of unknown natal origin were assigned to their natal rivers using the juvenile fingerprints from QDFA approach. Only 18 adults originated from streams not included in the juvenile database. Although most of the adults showed a marked homing instinct, homing was not perfect, and some wild fish strayed into non-natal spawning areas. Returns of hatchery-reared fish as adult spawners represented 10% of the total sampled fish. Allocation of fish to natal tributaries or hatcheries illustrated the abundance and relative contributions of natal sources, important for the recovery of Atlantic salmon in this area.

scholarly journals Behavior of trap-and-transported Atlantic salmon spawners of hatchery origin in the Daugava River system (Latvia)

2019 ◽  
Vol 78 (2) ◽  
Author(s):  
Daniel Nyqvist ◽  
Matiss Zagars ◽  
Olle Calles ◽  
Claudio Comoglio
Keyword(s):  
Atlantic Salmon ◽  
River System ◽  
Spawning Habitat ◽  
Negative Effects ◽  
Large Reservoir ◽  
Handling Stress ◽  
Wild Salmon ◽  
Spawning Areas ◽  
Sea Ranching ◽  
Salmon Population

Where migrating fish have to pass multiple dams, very high passage performance is required at the series of obstacles to avoid accumulated negative effects of multiple dam passage. In some rivers, migrating fish are trapped, transported past several obstacles, and released to continue their migration. Such trap-and-transport solutions, however, have seldom been evaluated. In the Daugava River, Latvia, several dams with no functional fishways block the river for migrating fish. A remnant Atlantic salmon population is being sustained by a sea ranching regime, where returning spawners are caught and artificially spawned, the juveniles raised in hatcheries, and smolts released in to the river in time for their seaward migration. Hatchery released fish, however, differ substantially from wild conspecifics, and in Latvia, as elsewhere throughout the range of salmon, reduced dependency on hatchery production and the re-establishment of wild salmon populations are being discussed. In the Daugava River system, suitable spawning and rearing habitat remains upstream two dams and an associated large reservoir in a mainstem tributary, the Ogre River, offering the potential to restore a wild salmon population.  To explore the potential of a trap-and-transport solution to bring Atlantic salmon spawners in contact with remaining spawning grounds in the Daugava River system, spawners were caught, radio tagged, transported upstream of the two dams and the reservoir, and released to pursue their spawning migration in the tributary. Despite being unfamiliar with the river, some of the tagged spawners moved upstream, reaching areas up to 12 km from the release sites. Males were observed higher upstream in the river compared to females, and some males were tracked relatively close to potential salmon spawning habitat. Females, although displaying some movements in the lower parts of the river, were not observed close to any suitable spawning areas, highlighting potentially important sex differences in post trap-and-transport behaviour. Perhaps due to different responses to handling stress, such low post-transportation spawning success among females has the potential to negatively impact restoration efforts in the Daugava River system and elsewhere. The present study represents a first step towards the restoration of wild Daugava salmon, one of several unique Baltic Atlantic salmon populations, and a potential model for future restoration efforts.  

scholarly journals Restored river habitat provides a natural spawning area for a critically endangered landlocked Atlantic salmon population

PLoS ONE ◽  
2020 ◽  
Vol 15 (5) ◽  
pp. e0232723
Author(s):  
Tuomas Leinonen ◽  
Jorma Piironen ◽  
Marja-Liisa Koljonen ◽  
Jarmo Koskiniemi ◽  
Antti Kause
Keyword(s):  
Atlantic Salmon ◽  
Critically Endangered ◽  
River Habitat ◽  
Natural Spawning ◽  
Spawning Area ◽  
Salmon Population

Size selection from fishways and potential evolutionary responses in a threatened Atlantic salmon population

2017 ◽  
Vol 33 (7) ◽  
pp. 1004-1015 ◽  
Author(s):  
G. A. Maynard ◽  
M. T. Kinnison ◽  
J. D. Zydlewski
Keyword(s):  
Atlantic Salmon ◽  
Size Selection ◽  
Salmon Population

Relationship of upstream migrating adult Atlantic salmon (Salmo salar) and stream discharge within Catamaran Brook, New Brunswick

2007 ◽  
Vol 64 (3) ◽  
pp. 563-573 ◽  
Author(s):  
Sean C Mitchell ◽  
Richard A Cunjak
Keyword(s):  
Body Size ◽  
Atlantic Salmon ◽  
New Brunswick ◽  
Salmo Salar ◽  
Predictive Ability ◽  
River System ◽  
Low Flow ◽  
Stream Discharge ◽  
Atlantic Salmon Salmo Salar ◽  
Adult Abundance

Stream discharge has long been associated with abundance of returning adult spawning salmonids to streams and may also affect body size distribution of adult salmon as low flows interfere with returns of larger-bodied fish. We examined these relationships of abundance and body size within Catamaran Brook, a third-order tributary to the Miramichi River system of New Brunswick, Canada, to investigate the causes of a declining trend in annual returns of Atlantic salmon (Salmo salar) to this stream. Regression models of adult abundance, proportion of the run as grilse, and body size of returning adults as functions of maximum daily stream discharge during the period of upstream spawner migration were constructed. Adult abundance shows a logarithmic relationship with stream discharge and provides good predictive ability, while appearing to not be significantly related to adult abundance in the larger Miramichi system. The proportion as grilse in the run and female body size are also logarithmically related to stream discharge, with low flow years being very influential in the regressions. These relationships of Atlantic salmon population abundance and body size characteristics have implications with respect to stock integrity and production of the following generation.

Advances in Fish Tagging and Marking Technology

2012 ◽  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Release Time ◽  
Tag Identification ◽  
Penobscot River ◽  
Salmon Population ◽  
Declining Populations ◽  
Simple Change ◽  
Using Data ◽  
Made In

<i>Abstract</i>.—Atlantic salmon <i>Salmo salar </i>smolts are stocked in the Penobscot River, Maine to supplement declining populations. Since 2000, approximately 550,000 hatchery smolts are annually released into the river, of which 32% of these (175,000) were marked with visual implant elastomer (VIE) tags indicating release time and location. Our study found that tag colors of adult returns were often misread due to confusion between green and yellow marks and between red and pink marks. Using data collected on mark readings in a controlled hatchery environment, we corrected for tag identification errors made in the field, thereby allowing adjustments to be made in the marked returns to accurately assess the number of returns from multiple stocking groups. When adult returns from multiple stocking groups were compared, significant differences were detected between stocking groups, including a three-fold difference between two of the stocking groups. Hence, a simple change in smolt stocking locations and times may be of value in the recovery of the Penobscot River salmon population.

scholarly journals Stable isotopes suggest the location of marine feeding grounds of South European Atlantic salmon in Greenland

2020 ◽  
Vol 77 (2) ◽  
pp. 593-603 ◽  
Author(s):  
Ana Almodóvar ◽  
Graciela G Nicola ◽  
Daniel Ayllón ◽  
Clive N Trueman ◽  
Ian Davidson ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Population Decline ◽  
Migration Route ◽  
North Atlantic Current ◽  
Migration Routes ◽  
Δ13c And Δ15n ◽  
Δ13c Values ◽  
The North ◽  
Salmon Population ◽  
And Migration

Abstract Historical data on the oceanic distribution and migration routes of southernmost Atlantic salmon Salmo salar populations from Europe are almost non-existent, as no rigorous tagging initiatives have been conducted. Here, we used stable isotope data (δ13C and δ15N) of historic scale collections to identify the potential marine feeding areas of the largest salmon population in the Iberian Peninsula. Data were compared with published datasets from Northern Ireland, Wales, south England, and northeast UK coast, which correspond to series between 15- and 33-year long within the time period from 1958 to 2009. Temporal covariation in sea surface temperature, primary productivity, and δ13C values suggests that feeding areas of Iberian salmon are located around Greenland, both in the Labrador and the Irminger seas. Furthermore, δ13C values of Atlantic salmon from Canadian rivers reported in the literature are similar to those found in individuals from Spanish rivers. Our results suggest that Iberian salmon follow a westerly migration route towards Greenland instead of following the easterly branch of the North Atlantic current into the Norwegian Sea. Characterization of feeding patterns and migration routes might help to understand the causes of ongoing population decline and establish targeted conservation programmes for threatened Iberian salmon.

Sperm motility and offspring pre- and post-hatching survival in hybridization crosses among a landlocked and two anadromous Atlantic salmon populations: implications for conservation

2020 ◽  
Author(s):  
Aslak Tiuna Eronen ◽  
Jukka Kekäläinen ◽  
Jorma Piironen ◽  
Pekka Hyvärinen ◽  
Hannu Huuskonen ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Sperm Motility ◽  
First Generation ◽  
Hybrid Vigor ◽  
Outbreeding Depression ◽  
Genetic Rescue ◽  
Low Genetic Diversity ◽  
Salmon Eggs ◽  
Salmon Population ◽  
Lake Saimaa

The landlocked salmon (Salmo salar m. sebago) endemic to Lake Saimaa, Finland, is critically endangered and severely threatened by low genetic diversity and inbreeding. To explore the possibility of increasing the genetic diversity of threatened salmon populations by controlled hybridization (genetic rescue), we studied sperm motility and offspring pre- and post-hatching survival in hybridization crosses of landlocked salmon with two geographically close anadromous salmon populations (Rivers Neva and Tornio) relative to the pure-bred populations. While some degree of gametic incompatibility between landlocked and Tornio salmon cannot be ruled out, there were no indications of outbreeding depression in survival traits in these first-generation hybridizations. Instead, pre-hatching survival of landlocked salmon eggs fertilized with Neva salmon sperm and post-hatching survival of anadromous salmon eggs fertilized with landlocked salmon sperm were higher than in pure-bred landlocked salmon. These differences might imply genetic rescue effects (hybrid vigor), although there were also strong maternal effects involved. Our results on early viability point to the possibility of applying genetic rescue to the landlocked salmon population by hybridization with an anadromous population.

The influence of discharge, current speed, and development on the downstream dispersal of larval nase (Chondrostoma nasus) in the River Danube

2018 ◽  
Vol 75 (2) ◽  
pp. 247-259 ◽  
Author(s):  
Aaron Lechner ◽  
Hubert Keckeis ◽  
Martin Glas ◽  
Michael Tritthart ◽  
Helmut Habersack ◽  
...  
Keyword(s):  
Developmental Stage ◽  
Release Site ◽  
Current Speed ◽  
Low Flow ◽  
Critical Conditions ◽  
Dispersal Patterns ◽  
Hydraulic Conditions ◽  
River Danube ◽  
Chondrostoma Nasus ◽  
Fish Activity

We investigated the mode (active versus passive) of larval downstream dispersal and its influencing factors in the nase carp (Chondrostoma nasus). Marked larvae (early and later stages), together with equivalent numbers of passive particles, were released in the main channel of the River Danube (Austria) at different flow (low, high) and current (over-critical, under-critical) conditions. Larvae and particles were recaptured with stationary nets at varying distances from release. We assumed that differences in the spatial dispersal patterns between larvae and particles were due to fish activity. We hypothesized that river discharge, developmental stage, current speed, and distance from release would influence these differences. We found that activity was independent of developmental stage or current speed at release, although activity was higher during low flow conditions. It may be that larvae deliberately enter the current during low flow, because the hydraulic conditions facilitate active dispersal. Furthermore, activity was greatest near the release site. This might be due to an intrinsically greater activity when fish are placed into novel surroundings or a result of rheoreaction. The discharge-dependent dispersal patterns observed represent an important ecological link between flow and recruitment and demonstrate the importance of inshore conditions for the early life stages of fish in large rivers, especially with regard to river modification and restoration schemes.

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